1. Field of the Invention
The invention pertains to a method for producing a card sliver using a carding machine including working elements wherein the condition of the working elements deteriorates as the machine operating time increases, the method comprising periodically resetting the working elements for the purpose of compensating, at least partially, the deterioration in the condition of the working elements; and a carding machine for carrying out this method.
2. Discussion of the Background of the Invention and Material Information
On each side of a conventional revolving flat card there is a so-called flexible bend which can be adjusted relative to the corresponding side shield for the purpose of setting the carding gap (between the clothing of the flat bars and the carding cylinder clothing). This adjustment can be made manually, according to German Utility Model DE-Gbm 9313633.
It is also known, in the case of modern revolving flat cards, for example in the case of Applicants' own C 50 card, that the quality of the produced card silver is checked at regular time intervals using a laboratory instrument. The card clothing teeth are visually assessed by the responsible foreman of the spinning operation. If the latter determines, on the basis of his inspections and the operating period, that the quality is falling below a predetermined standard, then the card must be stopped so that the teeth of the carding cylinder clothing, and also, if necessary, the flat clothing can be reground. This inspection task is frequently performed by the manufacturers of the card clothing within the context of service contracts.
Following the grinding it is necessary to reset the existing carding gap, which has been enlarged by wear and the grinding operation. Generally three to five setting elements are provided on the flexible bend for this purpose, on each side of the card. The carding gap is measured at different points by means of a blade gauge and then set. These tasks are known to be time-consuming and result in stoppage times of up to one day on a single card. Obviously, however, the spinning operation requires full utilization of the machine operating times and therefore seeks to minimize the stoppage times for inspection of the machines. For this reason, in many spinning operations this inspection work is not carried out until the last moment, i.e., when the quality of the produced card sliver is still only just adequate or is even already below the tolerance limit. In view of this unsatisfactory situation, Applicants have set forth various proposals for automatic grinding of the carding cylinder clothing in European Patent Applications EP-A-497736 and EP-A-0 565 4860. The latter document, for example, provides for a controller for the application of a grinding element at periodic operating intervals. The use of automatic grinding enables the quality of the produced card sliver to be maintained over a certain period of time and within a defined tolerance range. However, it still remains necessary to reset the carding gap by hand.
It is the task or object of the present invention to further reduce the adjustment work on the card without adversely affecting the quality of the produced card sliver.